Driveline/ Gearbox Noise when Unloaded in 6th

Hi,
if you do have any luck re discussions on an auto please PM me as I too would be interested--so far most people I have spoken who have tried to do auto pumas have had lots of issues and say not to do it--yet I know Grinna in Wauchope who has been developing the 3.2 conversion into the pumas has also started development on an auto conversion, but have not heard from him in a while. Some of the leading LR independents feel the conversion to auto problematic, but I am hopeful. Please keep us all informed! Incidentally, Award Diffs in Seven Hills are puma gearbox experts and do some of the dealer's warranty rebuilds--I know because they did my son's--maybe give them a call--they have done a LOT. Thanks,
Alan [bighmmm]

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Originally Posted by alan48

Hi,
if you do have any luck re discussions on an auto please PM me as I too would be interested--so far most people I have spoken who have tried to do auto pumas have had lots of issues and say not to do it--yet I know Grinna in Wauchope who has been developing the 3.2 conversion into the pumas has also started development on an auto conversion, but have not heard from him in a while. Some of the leading LR independents feel the conversion to auto problematic, but I am hopeful. Please keep us all informed! Incidentally, Award Diffs in Seven Hills are puma gearbox experts and do some of the dealer's warranty rebuilds--I know because they did my son's--maybe give them a call--they have done a LOT. Thanks,
Alan [bighmmm]

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Award Diffs closed last year.

The 6R80 auto from the Ranger and BBT50 protrudes on the drivers side affecting clearance of the front prop shaft. The ZF 6HP26 is slimmer and might not pose the same problem. Sorry Bobby for the off topic

I think the bigger, heavier pumas need slightly different gearing to the standard. 6th gear doesn't let the engine rev high enough for 100 - 110km/h.
To get around the strength problem of 6th, I'd like to re-gear my driveline to cruise in 5th which is direct drive. Either by changing the high gear of the transfer case or larger diameter tyres.

Mine is doing about 2100 revs at 100 kmh in 6th, and quite happy from there upwards.
I think the real problem is when people let it go too slow in 6th, down to 80kmh or even lower. At 80 kmh I find it is much happier in 5th. Its not an auto and the gears have to be used.

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Originally Posted by DiscoMick

Mine is doing about 2100 revs at 100 kmh in 6th, and quite happy from there upwards.
I think the real problem is when people let it go too slow in 6th, down to 80kmh or even lower. At 80 kmh I find it is much happier in 5th. Its not an auto and the gears have to be used.

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Exactly. I don't like going under 100 in top gear unless coasting down a grade or with very light load on the engine.
I wish someone made a miniature Road Ranger gearbox that would fit in these.

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Originally Posted by Beery

Exactly. I don't like going under 100 in top gear unless coasting down a grade or with very light load on the engine.
I wish someone made a miniature Road Ranger gearbox that would fit in these.

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I used to be terrible at going too slowly in 6th but after a great weekend with Chook and Summit, I stopped using it until I was doing at least 100kph.

Will assess options and if I go down the auto route, I'll keep everyone updated.

Well, I took a punt and ordered a new gearbox from Ashcroft, with the shaft upgrade added. The boys at KLR installed it along with a new clutch just in time for my drive up to Bundella last weekend and unfortunately I can report that the noise is still occurring, in exactly the same conditions....100kph+ in sixth gear, on flat or decline, foot removed from loud pedal. Rattly rattly not ouchy grindy. Definitely seems to be coming from the left of me and toward the front but I can't determine if it's the box, the diff or the engine.

I've shot Ashcroft an email to ask for their thoughts.

Next potential culprit could be the front ATB I suppose (I don't recall ever having heard the noise prior to having the ATBs installed) but I struggle to see how an issue in the diff housing would only occur at 100kph in gear unloaded but not with the clutch in or in neutral.

Feeling decidedly deflated.

Bobby
May sound stupid but I’ve heard of similar symptoms that turned out to be a loose plate rattling inside the cat. converter

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Originally Posted by Phil B

Bobby
May sound stupid but I’ve heard of similar symptoms that turned out to be a loose plate rattling inside the cat. converter

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Hey Bobby, if that was the cause wouldn't it just compel you to stick a hot poker in your eye while clamping a vice on your money bags?

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Originally Posted by Phil B

Bobby
May sound stupid but I’ve heard of similar symptoms that turned out to be a loose plate rattling inside the cat. converter

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While the box was out they also cut the cat out so this can't be the culprit, but I appreciate the suggestion, thank you Phil.

Dave Ashcroft has suggested that it could be the front diff and to remove the front prop shaft and see if the noise still occurs. If it does turn out to be the diff I'll assume it's a warranty fix as KLR installed the ATB and HD shafts and flanges etc only a few months ago.

We shall see....

Currently waiting for Brad to source me a second hand ABS pump for an unrelated issue so once he's got one of those, I'll take it in and we'll have a good look at it.